1. From the Departments of Emergency Medicine (P.A.S., W.J.M., S.M.F., L.B.M.) and Biostatistics (Z.X., J.D.K.) and the Stroke Program (P.A.S., W.J.M., L.B.M.), University of Michigan, Ann Arbor, Mich; the Department of Epidemiology and Biostatistics (M.N.H.), University of California, San Francisco, Calif; the Emergency Department (M.W.W.), Lakeland Community Hospital, Niles, Mich; and the Emergency Department (S.U.K.), Holland Hospital, Holland, Mich.